This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Percentile Analysis for Differential Gene Expression (PADGE) is a novel tool for identifying genes differentially expressed between two groups of heterogeneous samples. PADGE was designed to compare expression profiles of sample subgroups at a series of percentile cutoffs and to examine the trend of relative expression between sample classes as expression level increases. For comparative analysis, all sample statistical analysis (t test or Wilcoxon rank sum test), the COPA approach (Tomlins et al, Science, 2005) and Kurtosis (Teschendorff, et al, Bioinformatics, 2006) are also implemented and their results are displayed side by side with PADGE, providing a resource of web-based tools for analysis of heterogeneous expression patterns